Shipbuilders rally in Adelaide over subs

Several hundred shipbuilders have rallied in Adelaide calling on Prime Minister Malcolm Turnbull to stand by the government's promise to build 12 submarines in Adelaide.

The workers marched from Victoria Square to the commonwealth parliamentary offices, voicing their concerns that their jobs remain at risk.

"Shipbuilders across the country are sick to death of politicians making promises prior to an election and then breaking them," Australian Manufacturing Workers' Union (AMWU) assistant national secretary Glenn Thompson told the rally.

"We're sending a loud clear message to Prime Minister Turnbull. Stand by the promise to build 12 submarines in Australia and in South Australia."

Federal Labor MP Nick Butler told the rally the federal government faced a clear choice, back the workers in the Adelaide shipyards or "sell your jobs down the river".

Friday's rally came after the AMWU last week unveiled a series of billboards across Adelaide backing submarine construction in Adelaide.

The federal government is still undergoing a competitive evaluation process for the submarine contract.